The present invention generally relates to a system and method for transmitting medical imaging data. More particularly, the present invention relates to transmitting remotely controllable unprocessed medical imaging data over a network such as the Internet, an Intranet, or a wireless network to a remote site for viewing by an expert.
Medical imaging systems are typically used for a wide variety of applications in the field of medicine. For example, medical imaging systems such as ultrasound, CT scan, MRI, or X-ray systems, may be used for diagnosis or monitoring purposes. One type of medical imaging system commonly used in medicine is an ultrasound imaging system. Typical ultrasound imaging systems operate by transmitting ultrasonic sound waves into a patient's body using a transducer. The transducer is typically a device placed on the patient's body over the area to be imaged that is capable of sending and receiving ultrasonic sound waves. The ultrasonic sound waves sent by the transducer are reflected by the patient's internal bodily structures. The reflected ultrasonic sound waves transmitted into the patient's body may then be received by the transducer and transmitted to a data acquisition processor in the ultrasound imaging system.
The data acquisition processor typically converts the ultrasonic sound waves into digital, unprocessed ultrasound data. The unprocessed ultrasound data may then be transmitted to an ultrasound data processor. The ultrasound data processor may then perform pre-processing functions on the unprocessed ultrasound data resulting in pre-processed ultrasound data. The pre-processed ultrasound data may then be transferred to an ultrasound imaging processor in the ultrasound imaging system. The ultrasound imaging processor may then perform post-processing functions such as B-compression, dynamic range adjustments, or intensity threshold, for example, on the pre-processed ultrasound data resulting in post-processed ultrasound data. The post-processed data may then be transmitted to a scan converter. The scan converter of the post-processed ultrasound data may convert the post-processed ultrasound data into pixel image data in X-Y coordinates. The pixel image data may then be transmitted to a display console. The display console typically displays the final pixel image data so that a visual representation of the patient's internal bodily structures may be viewed or heard as an ultrasound image in real time by a doctor or technician for example.
Typical ultrasound imaging systems may also include a control console. The control console of the ultrasound imaging system typically includes a number of control devices. The control devices of the control console may be used by the technician or doctor to manipulate the parameters of the pre-processed or post-processed ultrasound data. The manipulation of the parameters of the pre-processed or post-processed ultrasound data allows the technician to adjust or manipulate the displayed ultrasound images. Ultrasound imaging systems that allow the technician or an examining doctor to adjust or manipulate the displayed ultrasound images may provide for greater flexibility and control over an ultrasound examination. Typically, the examining doctor knows what ultrasound images need to be viewed and the how the ultrasound images need to be viewed in order to make an accurate diagnosis. Thus, by allowing the examining doctor to manipulate the displayed ultrasound images, the doctor can get the information and images needed to make an accurate diagnosis. However, not all ultrasound examinations may actually be performed with a doctor in the examination room.
In today's highly specialized medical society, expert doctors or specialists with skills in specific fields such as ultrasound examination and diagnosis for example, may not be available at every medical facility with ultrasound imaging systems. Specialists in ultrasound imaging may be particularly hard to find at medical facilities in remote or rural areas. Thus, traditionally, in rural areas where specialists were not available to perform an ultrasound examination, either the specialist may have been transported to the rural location, or the patient may have been transported to the specialist's location. However, transporting the specialist to the rural area may be undesirable because transportation of the specialist may be time consuming or expensive. Additionally, transporting the patient may also be undesirable because transportation of the patient may also be time consuming or possibly dangerous. Therefore, in response to the fact that not all medical facilities with ultrasound imaging systems may have specialists on-site, remotely viewable ultrasound imaging systems have been developed. Remotely viewable ultrasound imaging systems typically allow a remotely located specialist to view ultrasound images taken from an on-site ultrasound imaging system. That is, a technician may actually perform the ultrasound procedure on-site, while an ultrasound specialist may view the ultrasound images at a remote location.
Typical remotely viewable ultrasound imaging systems may operate by transmitting the scan converted pixel image data over an Internet connection from the on-site facility to the remote location. The pixel image data may typically be compressed on-site using a video data compression format such as MPEG for example, and then transmitted over the Internet to the remote location. At the remote location, a remote terminal may be used to decode the compressed data and display the ultrasound images to the remote specialist. The remote specialist may then be able to diagnose or view the ultrasound images being taken and manipulated by the technician. While typical remotely viewable ultrasound imaging systems may allow a remotely located specialist to view ultrasound data, typical systems may suffer from some significant drawbacks.
One drawback that may exist in typical remotely viewable ultrasound imaging systems is a choppy video feed or transmission lag. Typical scan conversion functions performed on the post-processed ultrasound data by the ultrasound data processor as discussed above, may result in a significant increase in the size of the ultrasound data. For example, one video frame of unprocessed ultrasound data may represent approximately 50 kilobits of data, while one frame of scan converted post-processed ultrasound data may represent approximately 1 megabyte of data. Typical ultrasound imaging systems may display video at 30 or more frames per second for real time video. Thus, transmitting the relatively large pixel image data over the limited bandwidth of an Internet connection may result in a transmission lag, or transmission of data at a slower rate than required for real time video at 30 framer per second. Delivering video data at a slower rate than required for real time video at 30 frames per second may result in reduced frame rates, which may result in a choppy video stream. A choppy video stream may be undesirable in ultrasound imaging systems because real time imaging is highly desirable for allowing the specialist to make accurate diagnoses or readings of the ultrasound image.
An additional drawback that may exist in typical remotely viewable ultrasound imaging systems is loss of image quality. Because of the limited bandwidth available over the Internet and the relatively large size of the pixel image data as discussed above, the pixel image data may typically be significantly compressed by hardware or software prior to transmission to the remote location. Typical lossy video compression algorithms such as MPEG may result in lost data during the transfer from the on-site location to the remote location. Thus, when the remote viewer decompresses the compressed data, degradation in image quality may occur as a result of the lost data. Degradation in image quality may be undesirable in ultrasound imaging systems because high quality images are highly desirable for allowing the specialist to make accurate diagnoses or readings of the ultrasound image. In order to fit the given bandwidth, the compression ratio typically must be high which results in a higher data loss in many cases.
Another drawback that may exist in typical remotely viewable ultrasound imaging systems is the lack of control over the ultrasound examination by the remotely located specialist. Because the remote terminal typically receives the pixel image data after it has been scan converted, the remote specialist may not be able to perform many of the pre-processing or post-processing functions or operations on the ultrasound data available to the technician performing the ultrasound imaging. The technician performing the ultrasound imaging may typically be able to manipulate or adjust the parameters of the pre-processed and post-processed ultrasound data using the on-site console controls of the ultrasound imaging system as discussed above. However, since the remote specialist receives the pixel image data at such a late stage in the data cycle, the remote specialist may typically be unable to adjust the pre-processing or post-processing functions such as B-compression, dynamic range adjustments, or intensity threshold for example, from the remote terminal. Instead, the remote specialist may only be able to adjust the viewing parameters of the ultrasound image such as contrast, smoothness, brightness, or resizing for example, at the remote terminal. Thus, the remote specialist may be restricted to viewing the ultrasound images as dictated by the technician performing the ultrasound examination.
Also, because an unskilled technician may not know what may be important to display to the remote specialist, the unskilled technician may transmit less than optimal ultrasound images to the remote expert which may result in difficult diagnoses or inaccurate diagnoses by the remote specialist. Thus, the lack of control of the imaging operation on the part of the remote specialist is a considerable drawback. Additionally, it would be highly desirable to provide remote specialist with the ability to control at least part of the imaging operation because typically only the remote specialist typically knows what ultrasound images are desired to be viewed and how to view the images in order to make an accurate diagnosis.
Thus, a need exists for a medical imaging system the provides real-time, high resolution images to a remote expert for evaluation. Additionally, due to the drawbacks discussed above that may occur in typical remotely viewable ultrasound imaging systems, a need exists for a remotely viewable medical imaging system capable of transmitting smooth, high quality, real time ultrasound data to a remote terminal. Also, a need exists for such a medical imaging system that allows a remote expert to exert at least some control over the imaging operation. More specifically, a need further exists for a remotely viewable medical imaging system that allows a remotely located operator to have the same control over the functionality of the medical imaging system as the technician performing the ultrasound imaging.